[PATCH net-next v5 0/6] selftests: net: multithreaded multiqueue iou-zcrx

[PATCH net-next v5 0/6] selftests: net: multithreaded multiqueue iou-zcrx

[Juanlu Herrero]

This series extends the iou-zcrx selftests to be multithreaded while
preserving existing single-threaded tests.

Patches 1 and 2 are prep fixes/cleanups. Patch 3 refactors the server's
global state. Patches 4 and 5 add the multithreaded client and server.
Finally, patch 6 adds the python side multithreaded test case.

Changes since v4:
- In patch 4, make cfg_num_threads the default value and remove
  CONNS_PER_THREAD and associated ternary (David)
- Use reverse christmas tree for variables (Paolo, David)
- Address race condition identified by Sashiko (Paolo)
- use thread barriers to get rid of epoll in the main thread (David)
- Make napi id matcher helper take a connfd as a param and return the
  index directly (David)


v4: https://lore.kernel.org/netdev/20260729221825.42773-1-juanlu@fastmail.com/
v3: https://lore.kernel.org/netdev/20260722203950.58550-1-juanlu@fastmail.com/
v2: https://lore.kernel.org/netdev/20260418094907.3cde57ca@kernel.org/
v1: https://lore.kernel.org/netdev/20260408163816.2760-1-juanlu@fastmail.com/

Juanlu Herrero (6):
  selftests: net: fix get_refill_ring_size() to use its local variable
  selftests: net: remove unused variable in process_recvzc()
  selftests: net: refactor server state into struct thread_ctx
  selftests: net: add multithread client support to iou-zcrx
  selftests: net: add multithread server support to iou-zcrx
  selftests: net: add rss_multiqueue test variant to iou-zcrx

 .../testing/selftests/drivers/net/hw/Makefile |   7 +-
 .../selftests/drivers/net/hw/iou-zcrx.c       | 406 ++++++++++++------
 .../selftests/drivers/net/hw/iou-zcrx.py      |  50 ++-
 3 files changed, 332 insertions(+), 131 deletions(-)


base-commit: 3da8c3c8b8fa99505624b65ef590482f48e766b6
-- 
2.53.0-Meta

[PATCH net-next v5 1/6] selftests: net: fix get_refill_ring_size() to use its local variable

[Juanlu Herrero]

In preparation for multi-threaded rss selftests, fix
get_refill_ring_size() to use its local `size` variable instead of
assigning to the file-global `ring_size`.

Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Juanlu Herrero <juanlu@fastmail.com>
---
 tools/testing/selftests/drivers/net/hw/iou-zcrx.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
index f6a8fc5fac241..df6b622043438 100644
--- a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
+++ b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
@@ -132,10 +132,10 @@ static inline size_t get_refill_ring_size(unsigned int rq_entries)
 {
 	size_t size;
 
-	ring_size = rq_entries * sizeof(struct io_uring_zcrx_rqe);
+	size = rq_entries * sizeof(struct io_uring_zcrx_rqe);
 	/* add space for the header (head/tail/etc.) */
-	ring_size += page_size;
-	return ALIGN_UP(ring_size, page_size);
+	size += page_size;
+	return ALIGN_UP(size, page_size);
 }
 
 static void setup_zcrx(struct io_uring *ring)
-- 
2.53.0-Meta

[PATCH net-next v5 2/6] selftests: net: remove unused variable in process_recvzc()

[Juanlu Herrero]

Remove the unused `sqe` variable in preparation for the multiqueue rss
selftest changes to process_recvzc() in the following commits.

Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Juanlu Herrero <juanlu@fastmail.com>
---
 tools/testing/selftests/drivers/net/hw/iou-zcrx.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
index df6b622043438..c6dbd0ad53681 100644
--- a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
+++ b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
@@ -269,7 +269,6 @@ static void process_recvzc(struct io_uring *ring, struct io_uring_cqe *cqe)
 	unsigned rq_mask = rq_ring.ring_entries - 1;
 	struct io_uring_zcrx_cqe *rcqe;
 	struct io_uring_zcrx_rqe *rqe;
-	struct io_uring_sqe *sqe;
 	uint64_t mask;
 	char *data;
 	ssize_t n;
-- 
2.53.0-Meta

[PATCH net-next v5 3/6] selftests: net: refactor server state into struct thread_ctx

[Juanlu Herrero]

Move server-side state (io_uring ring, zcrx area, refill ring, receive
tracking) from global variables into a local struct thread_ctx. This is
a pure refactor with no behavior change: run_server still allocates a
single context on the stack and runs single-threaded, using io_uring
accept and recvzc as before.

This prepares the ground for the multithread server support in the
following commits, which spawns N worker threads each with their own
struct thread_ctx.

Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Juanlu Herrero <juanlu@fastmail.com>
---
 .../selftests/drivers/net/hw/iou-zcrx.c       | 156 +++++++++---------
 1 file changed, 80 insertions(+), 76 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
index c6dbd0ad53681..9b62fd0703e61 100644
--- a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
+++ b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
@@ -87,14 +87,18 @@ static unsigned int cfg_rx_buf_len;
 static bool cfg_dry_run;
 
 static char *payload;
-static void *area_ptr;
-static void *ring_ptr;
-static size_t ring_size;
-static struct io_uring_zcrx_rq rq_ring;
-static unsigned long area_token;
-static int connfd;
-static bool stop;
-static size_t received;
+
+struct thread_ctx {
+	struct io_uring		ring;
+	void			*area_ptr;
+	void			*ring_ptr;
+	size_t			ring_size;
+	struct io_uring_zcrx_rq	rq_ring;
+	unsigned long		area_token;
+	int			connfd;
+	bool			stop;
+	size_t			received;
+};
 
 static unsigned long gettimeofday_ms(void)
 {
@@ -138,7 +142,7 @@ static inline size_t get_refill_ring_size(unsigned int rq_entries)
 	return ALIGN_UP(size, page_size);
 }
 
-static void setup_zcrx(struct io_uring *ring)
+static void setup_zcrx(struct thread_ctx *ctx)
 {
 	unsigned int ifindex;
 	unsigned int rq_entries = 4096;
@@ -149,44 +153,44 @@ static void setup_zcrx(struct io_uring *ring)
 		error(1, 0, "bad interface name: %s", cfg_ifname);
 
 	if (cfg_rx_buf_len && cfg_rx_buf_len != page_size) {
-		area_ptr = mmap(NULL,
-				AREA_SIZE,
-				PROT_READ | PROT_WRITE,
-				MAP_ANONYMOUS | MAP_PRIVATE |
-				MAP_HUGETLB | MAP_HUGE_2MB,
-				-1,
-				0);
-		if (area_ptr == MAP_FAILED) {
+		ctx->area_ptr = mmap(NULL,
+				     AREA_SIZE,
+				     PROT_READ | PROT_WRITE,
+				     MAP_ANONYMOUS | MAP_PRIVATE |
+				     MAP_HUGETLB | MAP_HUGE_2MB,
+				     -1,
+				     0);
+		if (ctx->area_ptr == MAP_FAILED) {
 			printf("Can't allocate huge pages\n");
 			exit(SKIP_CODE);
 		}
 	} else {
-		area_ptr = mmap(NULL,
-				AREA_SIZE,
-				PROT_READ | PROT_WRITE,
-				MAP_ANONYMOUS | MAP_PRIVATE,
-				0,
-				0);
-		if (area_ptr == MAP_FAILED)
+		ctx->area_ptr = mmap(NULL,
+				     AREA_SIZE,
+				     PROT_READ | PROT_WRITE,
+				     MAP_ANONYMOUS | MAP_PRIVATE,
+				     0,
+				     0);
+		if (ctx->area_ptr == MAP_FAILED)
 			error(1, 0, "mmap(): zero copy area");
 	}
 
-	ring_size = get_refill_ring_size(rq_entries);
-	ring_ptr = mmap(NULL,
-			ring_size,
-			PROT_READ | PROT_WRITE,
-			MAP_ANONYMOUS | MAP_PRIVATE,
-			0,
-			0);
+	ctx->ring_size = get_refill_ring_size(rq_entries);
+	ctx->ring_ptr = mmap(NULL,
+			     ctx->ring_size,
+			     PROT_READ | PROT_WRITE,
+			     MAP_ANONYMOUS | MAP_PRIVATE,
+			     0,
+			     0);
 
 	struct io_uring_region_desc region_reg = {
-		.size = ring_size,
-		.user_addr = (__u64)(unsigned long)ring_ptr,
+		.size = ctx->ring_size,
+		.user_addr = (__u64)(unsigned long)ctx->ring_ptr,
 		.flags = IORING_MEM_REGION_TYPE_USER,
 	};
 
 	struct io_uring_zcrx_area_reg area_reg = {
-		.addr = (__u64)(unsigned long)area_ptr,
+		.addr = (__u64)(unsigned long)ctx->area_ptr,
 		.len = AREA_SIZE,
 		.flags = 0,
 	};
@@ -200,7 +204,7 @@ static void setup_zcrx(struct io_uring *ring)
 		.rx_buf_len = cfg_rx_buf_len,
 	};
 
-	ret = io_uring_register_ifq(ring, (void *)&reg);
+	ret = io_uring_register_ifq(&ctx->ring, (void *)&reg);
 	if (cfg_rx_buf_len && (ret == -EINVAL || ret == -EOPNOTSUPP ||
 			       ret == -ERANGE)) {
 		printf("Large chunks are not supported %i\n", ret);
@@ -209,64 +213,64 @@ static void setup_zcrx(struct io_uring *ring)
 		error(1, 0, "io_uring_register_ifq(): %d", ret);
 	}
 
-	rq_ring.khead = (unsigned int *)((char *)ring_ptr + reg.offsets.head);
-	rq_ring.ktail = (unsigned int *)((char *)ring_ptr + reg.offsets.tail);
-	rq_ring.rqes = (struct io_uring_zcrx_rqe *)((char *)ring_ptr + reg.offsets.rqes);
-	rq_ring.rq_tail = 0;
-	rq_ring.ring_entries = reg.rq_entries;
+	ctx->rq_ring.khead = (unsigned int *)((char *)ctx->ring_ptr + reg.offsets.head);
+	ctx->rq_ring.ktail = (unsigned int *)((char *)ctx->ring_ptr + reg.offsets.tail);
+	ctx->rq_ring.rqes = (struct io_uring_zcrx_rqe *)((char *)ctx->ring_ptr + reg.offsets.rqes);
+	ctx->rq_ring.rq_tail = 0;
+	ctx->rq_ring.ring_entries = reg.rq_entries;
 
-	area_token = area_reg.rq_area_token;
+	ctx->area_token = area_reg.rq_area_token;
 }
 
-static void add_accept(struct io_uring *ring, int sockfd)
+static void add_accept(struct thread_ctx *ctx, int sockfd)
 {
 	struct io_uring_sqe *sqe;
 
-	sqe = io_uring_get_sqe(ring);
+	sqe = io_uring_get_sqe(&ctx->ring);
 
 	io_uring_prep_accept(sqe, sockfd, NULL, NULL, 0);
 	sqe->user_data = 1;
 }
 
-static void add_recvzc(struct io_uring *ring, int sockfd)
+static void add_recvzc(struct thread_ctx *ctx, int sockfd)
 {
 	struct io_uring_sqe *sqe;
 
-	sqe = io_uring_get_sqe(ring);
+	sqe = io_uring_get_sqe(&ctx->ring);
 
 	io_uring_prep_rw(IORING_OP_RECV_ZC, sqe, sockfd, NULL, 0, 0);
 	sqe->ioprio |= IORING_RECV_MULTISHOT;
 	sqe->user_data = 2;
 }
 
-static void add_recvzc_oneshot(struct io_uring *ring, int sockfd, size_t len)
+static void add_recvzc_oneshot(struct thread_ctx *ctx, int sockfd, size_t len)
 {
 	struct io_uring_sqe *sqe;
 
-	sqe = io_uring_get_sqe(ring);
+	sqe = io_uring_get_sqe(&ctx->ring);
 
 	io_uring_prep_rw(IORING_OP_RECV_ZC, sqe, sockfd, NULL, len, 0);
 	sqe->ioprio |= IORING_RECV_MULTISHOT;
 	sqe->user_data = 2;
 }
 
-static void process_accept(struct io_uring *ring, struct io_uring_cqe *cqe)
+static void process_accept(struct thread_ctx *ctx, struct io_uring_cqe *cqe)
 {
 	if (cqe->res < 0)
 		error(1, 0, "accept()");
-	if (connfd)
+	if (ctx->connfd)
 		error(1, 0, "Unexpected second connection");
 
-	connfd = cqe->res;
+	ctx->connfd = cqe->res;
 	if (cfg_oneshot)
-		add_recvzc_oneshot(ring, connfd, page_size);
+		add_recvzc_oneshot(ctx, ctx->connfd, page_size);
 	else
-		add_recvzc(ring, connfd);
+		add_recvzc(ctx, ctx->connfd);
 }
 
-static void process_recvzc(struct io_uring *ring, struct io_uring_cqe *cqe)
+static void process_recvzc(struct thread_ctx *ctx, struct io_uring_cqe *cqe)
 {
-	unsigned rq_mask = rq_ring.ring_entries - 1;
+	unsigned int rq_mask = ctx->rq_ring.ring_entries - 1;
 	struct io_uring_zcrx_cqe *rcqe;
 	struct io_uring_zcrx_rqe *rqe;
 	uint64_t mask;
@@ -275,7 +279,7 @@ static void process_recvzc(struct io_uring *ring, struct io_uring_cqe *cqe)
 	int i;
 
 	if (cqe->res == 0 && cqe->flags == 0 && cfg_oneshot_recvs == 0) {
-		stop = true;
+		ctx->stop = true;
 		return;
 	}
 
@@ -284,56 +288,56 @@ static void process_recvzc(struct io_uring *ring, struct io_uring_cqe *cqe)
 
 	if (cfg_oneshot) {
 		if (cqe->res == 0 && cqe->flags == 0 && cfg_oneshot_recvs) {
-			add_recvzc_oneshot(ring, connfd, page_size);
+			add_recvzc_oneshot(ctx, ctx->connfd, page_size);
 			cfg_oneshot_recvs--;
 		}
 	} else if (!(cqe->flags & IORING_CQE_F_MORE)) {
-		add_recvzc(ring, connfd);
+		add_recvzc(ctx, ctx->connfd);
 	}
 
 	rcqe = (struct io_uring_zcrx_cqe *)(cqe + 1);
 
 	n = cqe->res;
 	mask = (1ULL << IORING_ZCRX_AREA_SHIFT) - 1;
-	data = (char *)area_ptr + (rcqe->off & mask);
+	data = (char *)ctx->area_ptr + (rcqe->off & mask);
 
 	for (i = 0; i < n; i++) {
-		if (*(data + i) != payload[(received + i)])
+		if (*(data + i) != payload[(ctx->received + i)])
 			error(1, 0, "payload mismatch at %d", i);
 	}
-	received += n;
+	ctx->received += n;
 
-	rqe = &rq_ring.rqes[(rq_ring.rq_tail & rq_mask)];
-	rqe->off = (rcqe->off & ~IORING_ZCRX_AREA_MASK) | area_token;
+	rqe = &ctx->rq_ring.rqes[(ctx->rq_ring.rq_tail & rq_mask)];
+	rqe->off = (rcqe->off & ~IORING_ZCRX_AREA_MASK) | ctx->area_token;
 	rqe->len = cqe->res;
-	io_uring_smp_store_release(rq_ring.ktail, ++rq_ring.rq_tail);
+	io_uring_smp_store_release(ctx->rq_ring.ktail, ++ctx->rq_ring.rq_tail);
 }
 
-static void server_loop(struct io_uring *ring)
+static void server_loop(struct thread_ctx *ctx)
 {
 	struct io_uring_cqe *cqe;
 	unsigned int count = 0;
 	unsigned int head;
 	int i, ret;
 
-	io_uring_submit_and_wait(ring, 1);
+	io_uring_submit_and_wait(&ctx->ring, 1);
 
-	io_uring_for_each_cqe(ring, head, cqe) {
+	io_uring_for_each_cqe(&ctx->ring, head, cqe) {
 		if (cqe->user_data == 1)
-			process_accept(ring, cqe);
+			process_accept(ctx, cqe);
 		else if (cqe->user_data == 2)
-			process_recvzc(ring, cqe);
+			process_recvzc(ctx, cqe);
 		else
 			error(1, 0, "unknown cqe");
 		count++;
 	}
-	io_uring_cq_advance(ring, count);
+	io_uring_cq_advance(&ctx->ring, count);
 }
 
 static void run_server(void)
 {
+	struct thread_ctx ctx = {};
 	unsigned int flags = 0;
-	struct io_uring ring;
 	int fd, enable, ret;
 	uint64_t tstop;
 
@@ -356,22 +360,22 @@ static void run_server(void)
 	flags |= IORING_SETUP_SUBMIT_ALL;
 	flags |= IORING_SETUP_CQE32;
 
-	io_uring_queue_init(512, &ring, flags);
+	io_uring_queue_init(512, &ctx.ring, flags);
 
-	setup_zcrx(&ring);
+	setup_zcrx(&ctx);
 	if (cfg_dry_run)
 		return;
 
 	if (listen(fd, 1024) < 0)
 		error(1, 0, "listen()");
 
-	add_accept(&ring, fd);
+	add_accept(&ctx, fd);
 
 	tstop = gettimeofday_ms() + 5000;
-	while (!stop && gettimeofday_ms() < tstop)
-		server_loop(&ring);
+	while (!ctx.stop && gettimeofday_ms() < tstop)
+		server_loop(&ctx);
 
-	if (!stop)
+	if (!ctx.stop)
 		error(1, 0, "test failed\n");
 }
 
-- 
2.53.0-Meta

[PATCH net-next v5 4/6] selftests: net: add multithread client support to iou-zcrx

[Juanlu Herrero]

Add pthreads to the iou-zcrx client so that multiple connections can be
established simultaneously. Each client thread connects to the server
and sends its payload independently.

Introduce the -t option to control the number of threads (default 1),
preserving backwards compatibility with existing tests.

Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Juanlu Herrero <juanlu@fastmail.com>
---
 .../testing/selftests/drivers/net/hw/Makefile |  2 +-
 .../selftests/drivers/net/hw/iou-zcrx.c       | 35 +++++++++++++++++--
 2 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/hw/Makefile b/tools/testing/selftests/drivers/net/hw/Makefile
index 78bb0169350b2..37023ba580de7 100644
--- a/tools/testing/selftests/drivers/net/hw/Makefile
+++ b/tools/testing/selftests/drivers/net/hw/Makefile
@@ -91,5 +91,5 @@ include ../../../net/ynl.mk
 include ../../../net/bpf.mk
 
 ifeq ($(HAS_IOURING_ZCRX),y)
-$(OUTPUT)/iou-zcrx: LDLIBS += -luring
+$(OUTPUT)/iou-zcrx: LDLIBS += -luring -lpthread
 endif
diff --git a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
index 9b62fd0703e61..f793a6c04e412 100644
--- a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
+++ b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
@@ -4,6 +4,7 @@
 #include <error.h>
 #include <fcntl.h>
 #include <limits.h>
+#include <pthread.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -85,6 +86,7 @@ static int cfg_send_size = SEND_SIZE;
 static struct sockaddr_in6 cfg_addr;
 static unsigned int cfg_rx_buf_len;
 static bool cfg_dry_run;
+static int cfg_num_threads = 1;
 
 static char *payload;
 
@@ -379,7 +381,7 @@ static void run_server(void)
 		error(1, 0, "test failed\n");
 }
 
-static void run_client(void)
+static void *client_worker(void *arg)
 {
 	ssize_t to_send = cfg_send_size;
 	ssize_t sent = 0;
@@ -405,12 +407,36 @@ static void run_client(void)
 	}
 
 	close(fd);
+	return NULL;
+}
+
+static void run_client(void)
+{
+	int total_conns = cfg_num_threads * cfg_num_threads;
+	pthread_t *threads;
+	int i, ret;
+
+	threads = calloc(total_conns, sizeof(*threads));
+	if (!threads)
+		error(1, 0, "calloc()");
+
+	for (i = 0; i < total_conns; i++) {
+		ret = pthread_create(&threads[i], NULL, client_worker, NULL);
+		if (ret)
+			error(1, ret, "pthread_create()");
+	}
+
+	for (i = 0; i < total_conns; i++)
+		pthread_join(threads[i], NULL);
+
+	free(threads);
 }
 
 static void usage(const char *filepath)
 {
 	error(1, 0, "Usage: %s (-4|-6) (-s|-c) -h<server_ip> -p<port> "
-		    "-l<payload_size> -i<ifname> -q<rxq_id>", filepath);
+		    "-l<payload_size> -i<ifname> -q<rxq_id> -t<num_threads>",
+		    filepath);
 }
 
 static void parse_opts(int argc, char **argv)
@@ -428,7 +454,7 @@ static void parse_opts(int argc, char **argv)
 		usage(argv[0]);
 	cfg_payload_len = max_payload_len;
 
-	while ((c = getopt(argc, argv, "sch:p:l:i:q:o:z:x:d")) != -1) {
+	while ((c = getopt(argc, argv, "sch:p:l:i:q:o:z:x:dt:")) != -1) {
 		switch (c) {
 		case 's':
 			if (cfg_client)
@@ -469,6 +495,9 @@ static void parse_opts(int argc, char **argv)
 		case 'd':
 			cfg_dry_run = true;
 			break;
+		case 't':
+			cfg_num_threads = strtoul(optarg, NULL, 0);
+			break;
 		}
 	}
 
-- 
2.53.0-Meta

[PATCH net-next v5 5/6] selftests: net: add multithread server support to iou-zcrx

[Juanlu Herrero]

Run the iou-zcrx server as N worker threads, each owning one receive
queue with its own io_uring and zero-copy receive (zcrx) ifq, so the
test can exercise multi-queue zero-copy receive.

The main thread owns the listening socket, accepts connections, and
dispatches each to the worker owning the queue it landed on by matching
SO_INCOMING_NAPI_ID against per-queue NAPI IDs.

Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Juanlu Herrero <juanlu@fastmail.com>
---
 .../testing/selftests/drivers/net/hw/Makefile |   5 +-
 .../selftests/drivers/net/hw/iou-zcrx.c       | 262 +++++++++++++-----
 2 files changed, 195 insertions(+), 72 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/hw/Makefile b/tools/testing/selftests/drivers/net/hw/Makefile
index 37023ba580de7..f613c88fffc53 100644
--- a/tools/testing/selftests/drivers/net/hw/Makefile
+++ b/tools/testing/selftests/drivers/net/hw/Makefile
@@ -13,10 +13,6 @@ else
 $(warning excluding iouring tests, liburing not installed or too old)
 endif
 
-TEST_GEN_FILES := \
-	$(COND_GEN_FILES) \
-# end of TEST_GEN_FILES
-
 TEST_PROGS = \
 	csum.py \
 	devlink_rate_cross_esw.py \
@@ -74,6 +70,7 @@ TEST_INCLUDES := \
 YNL_GEN_FILES := \
 	ncdevmem \
 	toeplitz \
+	$(COND_GEN_FILES) \
 # end of YNL_GEN_FILES
 TEST_GEN_FILES += $(YNL_GEN_FILES)
 TEST_GEN_FILES += $(patsubst %.c,%.o,$(wildcard *.bpf.c))
diff --git a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
index f793a6c04e412..008d3f4b76263 100644
--- a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
+++ b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
@@ -38,6 +38,8 @@
 #include <sys/wait.h>
 
 #include <liburing.h>
+#include <ynl.h>
+#include "netdev-user.h"
 
 #define SKIP_CODE	42
 
@@ -90,6 +92,8 @@ static int cfg_num_threads = 1;
 
 static char *payload;
 
+#define MAX_CONNS_PER_THREAD	64
+
 struct thread_ctx {
 	struct io_uring		ring;
 	void			*area_ptr;
@@ -97,9 +101,15 @@ struct thread_ctx {
 	size_t			ring_size;
 	struct io_uring_zcrx_rq	rq_ring;
 	unsigned long		area_token;
-	int			connfd;
-	bool			stop;
-	size_t			received;
+	int			queue_id;
+	int			napi_id;
+	pthread_barrier_t	*setup_done;
+	pthread_barrier_t	*dispatch_done;
+
+	int			connfds[MAX_CONNS_PER_THREAD];
+	size_t			received[MAX_CONNS_PER_THREAD];
+	int			oneshot_recvs[MAX_CONNS_PER_THREAD];
+	int			nr_conns;
 };
 
 static unsigned long gettimeofday_ms(void)
@@ -199,7 +209,7 @@ static void setup_zcrx(struct thread_ctx *ctx)
 
 	struct t_io_uring_zcrx_ifq_reg reg = {
 		.if_idx = ifindex,
-		.if_rxq = cfg_queue_id,
+		.if_rxq = ctx->queue_id,
 		.rq_entries = rq_entries,
 		.area_ptr = (__u64)(unsigned long)&area_reg,
 		.region_ptr = (__u64)(unsigned long)&region_reg,
@@ -224,53 +234,32 @@ static void setup_zcrx(struct thread_ctx *ctx)
 	ctx->area_token = area_reg.rq_area_token;
 }
 
-static void add_accept(struct thread_ctx *ctx, int sockfd)
+static void add_recvzc(struct thread_ctx *ctx, int conn_idx)
 {
 	struct io_uring_sqe *sqe;
 
 	sqe = io_uring_get_sqe(&ctx->ring);
 
-	io_uring_prep_accept(sqe, sockfd, NULL, NULL, 0);
-	sqe->user_data = 1;
-}
-
-static void add_recvzc(struct thread_ctx *ctx, int sockfd)
-{
-	struct io_uring_sqe *sqe;
-
-	sqe = io_uring_get_sqe(&ctx->ring);
-
-	io_uring_prep_rw(IORING_OP_RECV_ZC, sqe, sockfd, NULL, 0, 0);
+	io_uring_prep_rw(IORING_OP_RECV_ZC, sqe, ctx->connfds[conn_idx],
+			 NULL, 0, 0);
 	sqe->ioprio |= IORING_RECV_MULTISHOT;
-	sqe->user_data = 2;
+	sqe->user_data = conn_idx;
 }
 
-static void add_recvzc_oneshot(struct thread_ctx *ctx, int sockfd, size_t len)
+static void add_recvzc_oneshot(struct thread_ctx *ctx, int conn_idx, size_t len)
 {
 	struct io_uring_sqe *sqe;
 
 	sqe = io_uring_get_sqe(&ctx->ring);
 
-	io_uring_prep_rw(IORING_OP_RECV_ZC, sqe, sockfd, NULL, len, 0);
+	io_uring_prep_rw(IORING_OP_RECV_ZC, sqe, ctx->connfds[conn_idx],
+			 NULL, len, 0);
 	sqe->ioprio |= IORING_RECV_MULTISHOT;
-	sqe->user_data = 2;
+	sqe->user_data = conn_idx;
 }
 
-static void process_accept(struct thread_ctx *ctx, struct io_uring_cqe *cqe)
-{
-	if (cqe->res < 0)
-		error(1, 0, "accept()");
-	if (ctx->connfd)
-		error(1, 0, "Unexpected second connection");
-
-	ctx->connfd = cqe->res;
-	if (cfg_oneshot)
-		add_recvzc_oneshot(ctx, ctx->connfd, page_size);
-	else
-		add_recvzc(ctx, ctx->connfd);
-}
-
-static void process_recvzc(struct thread_ctx *ctx, struct io_uring_cqe *cqe)
+static void process_recvzc(struct thread_ctx *ctx, struct io_uring_cqe *cqe,
+			   int conn_idx)
 {
 	unsigned int rq_mask = ctx->rq_ring.ring_entries - 1;
 	struct io_uring_zcrx_cqe *rcqe;
@@ -280,8 +269,9 @@ static void process_recvzc(struct thread_ctx *ctx, struct io_uring_cqe *cqe)
 	ssize_t n;
 	int i;
 
-	if (cqe->res == 0 && cqe->flags == 0 && cfg_oneshot_recvs == 0) {
-		ctx->stop = true;
+	if (cqe->res == 0 && cqe->flags == 0 &&
+	    ctx->oneshot_recvs[conn_idx] == 0) {
+		ctx->nr_conns--;
 		return;
 	}
 
@@ -289,12 +279,13 @@ static void process_recvzc(struct thread_ctx *ctx, struct io_uring_cqe *cqe)
 		error(1, 0, "recvzc(): %d", cqe->res);
 
 	if (cfg_oneshot) {
-		if (cqe->res == 0 && cqe->flags == 0 && cfg_oneshot_recvs) {
-			add_recvzc_oneshot(ctx, ctx->connfd, page_size);
-			cfg_oneshot_recvs--;
+		if (cqe->res == 0 && cqe->flags == 0 &&
+		    ctx->oneshot_recvs[conn_idx]) {
+			add_recvzc_oneshot(ctx, conn_idx, page_size);
+			ctx->oneshot_recvs[conn_idx]--;
 		}
 	} else if (!(cqe->flags & IORING_CQE_F_MORE)) {
-		add_recvzc(ctx, ctx->connfd);
+		add_recvzc(ctx, conn_idx);
 	}
 
 	rcqe = (struct io_uring_zcrx_cqe *)(cqe + 1);
@@ -304,10 +295,10 @@ static void process_recvzc(struct thread_ctx *ctx, struct io_uring_cqe *cqe)
 	data = (char *)ctx->area_ptr + (rcqe->off & mask);
 
 	for (i = 0; i < n; i++) {
-		if (*(data + i) != payload[(ctx->received + i)])
+		if (*(data + i) != payload[(ctx->received[conn_idx] + i)])
 			error(1, 0, "payload mismatch at %d", i);
 	}
-	ctx->received += n;
+	ctx->received[conn_idx] += n;
 
 	rqe = &ctx->rq_ring.rqes[(ctx->rq_ring.rq_tail & rq_mask)];
 	rqe->off = (rcqe->off & ~IORING_ZCRX_AREA_MASK) | ctx->area_token;
@@ -320,28 +311,124 @@ static void server_loop(struct thread_ctx *ctx)
 	struct io_uring_cqe *cqe;
 	unsigned int count = 0;
 	unsigned int head;
-	int i, ret;
 
 	io_uring_submit_and_wait(&ctx->ring, 1);
 
 	io_uring_for_each_cqe(&ctx->ring, head, cqe) {
-		if (cqe->user_data == 1)
-			process_accept(ctx, cqe);
-		else if (cqe->user_data == 2)
-			process_recvzc(ctx, cqe);
-		else
-			error(1, 0, "unknown cqe");
+		process_recvzc(ctx, cqe, cqe->user_data);
 		count++;
 	}
 	io_uring_cq_advance(&ctx->ring, count);
 }
 
-static void run_server(void)
+static void *server_worker(void *arg)
 {
-	struct thread_ctx ctx = {};
-	unsigned int flags = 0;
-	int fd, enable, ret;
+	struct io_uring_params params = { };
+	struct thread_ctx *ctx = arg;
 	uint64_t tstop;
+	int i;
+
+	params.flags |= IORING_SETUP_COOP_TASKRUN;
+	params.flags |= IORING_SETUP_SINGLE_ISSUER;
+	params.flags |= IORING_SETUP_DEFER_TASKRUN;
+	params.flags |= IORING_SETUP_SUBMIT_ALL;
+	params.flags |= IORING_SETUP_CQE32;
+	params.flags |= IORING_SETUP_CQSIZE;
+	params.cq_entries = AREA_SIZE / page_size;
+
+	io_uring_queue_init_params(512, &ctx->ring, &params);
+	setup_zcrx(ctx);
+
+	if (cfg_dry_run)
+		return NULL;
+
+	pthread_barrier_wait(ctx->setup_done);
+	pthread_barrier_wait(ctx->dispatch_done);
+
+	for (i = 0; i < ctx->nr_conns; i++) {
+		if (cfg_oneshot) {
+			ctx->oneshot_recvs[i] = cfg_oneshot_recvs;
+			add_recvzc_oneshot(ctx, i, page_size);
+		} else {
+			add_recvzc(ctx, i);
+		}
+	}
+
+	tstop = gettimeofday_ms() + 5000;
+	while (ctx->nr_conns > 0 && gettimeofday_ms() < tstop)
+		server_loop(ctx);
+
+	if (ctx->nr_conns != 0)
+		error(1, 0, "test failed: %d connections incomplete",
+		      ctx->nr_conns);
+
+	return NULL;
+}
+
+static int query_napi_id(unsigned int ifindex, int queue_id)
+{
+	struct netdev_queue_get_req *req;
+	struct netdev_queue_get_rsp *rsp;
+	struct ynl_error yerr;
+	struct ynl_sock *ys;
+	int napi_id;
+
+	ys = ynl_sock_create(&ynl_netdev_family, &yerr);
+	if (!ys)
+		error(1, 0, "ynl_sock_create: %s", yerr.msg);
+
+	req = netdev_queue_get_req_alloc();
+	netdev_queue_get_req_set_ifindex(req, ifindex);
+	netdev_queue_get_req_set_type(req, NETDEV_QUEUE_TYPE_RX);
+	netdev_queue_get_req_set_id(req, queue_id);
+
+	rsp = netdev_queue_get(ys, req);
+	if (!rsp)
+		error(1, 0, "netdev_queue_get(q=%d): %s", queue_id,
+		      ys->err.msg);
+	if (!rsp->_present.napi_id)
+		error(1, 0, "netdev_queue_get(q=%d): napi_id not present",
+		      queue_id);
+
+	napi_id = rsp->napi_id;
+
+	netdev_queue_get_req_free(req);
+	netdev_queue_get_rsp_free(rsp);
+	ynl_sock_destroy(ys);
+
+	return napi_id;
+}
+
+static int find_thread_by_conn(struct thread_ctx *ctxs, int connfd)
+{
+	socklen_t len = sizeof(int);
+	int napi_id, i;
+
+	if (getsockopt(connfd, SOL_SOCKET, SO_INCOMING_NAPI_ID, &napi_id, &len))
+		error(1, errno, "getsockopt(SO_INCOMING_NAPI_ID)");
+
+	for (i = 0; i < cfg_num_threads; i++) {
+		if (ctxs[i].napi_id == napi_id)
+			return i;
+	}
+
+	error(1, 0, "unknown NAPI ID: %d", napi_id);
+	return -1;
+}
+
+static void run_server(void)
+{
+	pthread_barrier_t setup_done, dispatch_done;
+	int total_conns, accepted = 0, connfd;
+	struct thread_ctx *ctxs;
+	int fd, ret, enable, i;
+	unsigned int ifindex;
+	pthread_t *threads;
+
+	ctxs = calloc(cfg_num_threads, sizeof(*ctxs));
+	threads = calloc(cfg_num_threads, sizeof(*threads));
+	if (!ctxs || !threads)
+		error(1, 0, "calloc()");
 
 	fd = socket(AF_INET6, SOCK_STREAM, 0);
 	if (fd == -1)
@@ -356,29 +443,68 @@ static void run_server(void)
 	if (ret < 0)
 		error(1, 0, "bind()");
 
-	flags |= IORING_SETUP_COOP_TASKRUN;
-	flags |= IORING_SETUP_SINGLE_ISSUER;
-	flags |= IORING_SETUP_DEFER_TASKRUN;
-	flags |= IORING_SETUP_SUBMIT_ALL;
-	flags |= IORING_SETUP_CQE32;
+	pthread_barrier_init(&setup_done, NULL, cfg_num_threads + 1);
+	pthread_barrier_init(&dispatch_done, NULL, cfg_num_threads + 1);
+
+	for (i = 0; i < cfg_num_threads; i++) {
+		ctxs[i].queue_id = cfg_queue_id + i;
+		ctxs[i].setup_done = &setup_done;
+		ctxs[i].dispatch_done = &dispatch_done;
+	}
 
-	io_uring_queue_init(512, &ctx.ring, flags);
+	for (i = 0; i < cfg_num_threads; i++) {
+		ret = pthread_create(&threads[i], NULL,
+				     server_worker, &ctxs[i]);
+		if (ret)
+			error(1, ret, "pthread_create()");
+	}
 
-	setup_zcrx(&ctx);
 	if (cfg_dry_run)
-		return;
+		goto join;
 
 	if (listen(fd, 1024) < 0)
 		error(1, 0, "listen()");
 
-	add_accept(&ctx, fd);
+	pthread_barrier_wait(&setup_done);
 
-	tstop = gettimeofday_ms() + 5000;
-	while (!ctx.stop && gettimeofday_ms() < tstop)
-		server_loop(&ctx);
+	if (cfg_num_threads > 1) {
+		ifindex = if_nametoindex(cfg_ifname);
+		if (!ifindex)
+			error(1, 0, "bad interface name: %s", cfg_ifname);
+		for (i = 0; i < cfg_num_threads; i++)
+			ctxs[i].napi_id = query_napi_id(ifindex,
+							ctxs[i].queue_id);
+	}
+
+	total_conns = cfg_num_threads * cfg_num_threads;
+
+	while (accepted < total_conns) {
+		int idx = 0;
+
+		connfd = accept(fd, NULL, NULL);
+		if (connfd < 0)
+			error(1, errno, "accept()");
 
-	if (!ctx.stop)
-		error(1, 0, "test failed\n");
+		if (cfg_num_threads > 1)
+			idx = find_thread_by_conn(ctxs, connfd);
+
+		if (ctxs[idx].nr_conns >= MAX_CONNS_PER_THREAD)
+			error(1, 0, "worker %d connection overflow", idx);
+		ctxs[idx].connfds[ctxs[idx].nr_conns++] = connfd;
+		accepted++;
+	}
+
+	pthread_barrier_wait(&dispatch_done);
+
+join:
+	for (i = 0; i < cfg_num_threads; i++)
+		pthread_join(threads[i], NULL);
+
+	pthread_barrier_destroy(&setup_done);
+	pthread_barrier_destroy(&dispatch_done);
+	close(fd);
+	free(threads);
+	free(ctxs);
 }
 
 static void *client_worker(void *arg)
-- 
2.53.0-Meta

[PATCH net-next v5 6/6] selftests: net: add rss_multiqueue test variant to iou-zcrx

[Juanlu Herrero]

Add a rss_multiqueue Python test variant that exercises multi-queue
zero-copy receive on a single listening socket.

Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Juanlu Herrero <juanlu@fastmail.com>
---
 .../selftests/drivers/net/hw/iou-zcrx.py      | 50 ++++++++++++++++++-
 1 file changed, 48 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/hw/iou-zcrx.py b/tools/testing/selftests/drivers/net/hw/iou-zcrx.py
index b7a225fe4beae..c833535d8a03c 100755
--- a/tools/testing/selftests/drivers/net/hw/iou-zcrx.py
+++ b/tools/testing/selftests/drivers/net/hw/iou-zcrx.py
@@ -30,6 +30,13 @@ def create_rss_ctx(cfg):
     return int(values)
 
 
+def create_rss_ctx_multi(cfg, start, count):
+    """Create an RSS context spanning count queues from start, return its ID."""
+    output = ethtool(f"-X {cfg.ifname} context new start {start} equal {count}").stdout
+    values = re.search(r'New RSS context is (\d+)', output).group(1)
+    return int(values)
+
+
 def set_flow_rule(cfg):
     output = ethtool(f"-N {cfg.ifname} flow-type tcp6 dst-port {cfg.port} action {cfg.target}").stdout
     values = re.search(r'ID (\d+)', output).group(1)
@@ -127,17 +134,56 @@ def _require_ntuple(cfg):
         defer(ethtool, f"-K {cfg.ifname} ntuple-filters off")
 
 
+def rss_multiqueue(cfg):
+    """Steer the test flow to a multi-queue RSS context for multi-thread zcrx."""
+    channels = cfg.ethnl.channels_get({'header': {'dev-index': cfg.ifindex}})
+    channels = channels['combined-count']
+    if channels < 3:
+        raise KsftSkipEx('Test requires NETIF with at least 3 combined channels')
+
+    rings = cfg.ethnl.rings_get({'header': {'dev-index': cfg.ifindex}})
+    rx_rings = rings['rx']
+    hds_thresh = rings.get('hds-thresh', 0)
+
+    cfg.ethnl.rings_set({'header': {'dev-index': cfg.ifindex},
+                         'tcp-data-split': 'enabled',
+                         'hds-thresh': 0,
+                         'rx': 64})
+    defer(cfg.ethnl.rings_set, {'header': {'dev-index': cfg.ifindex},
+                                'tcp-data-split': 'unknown',
+                                'hds-thresh': hds_thresh,
+                                'rx': rx_rings})
+    defer(mp_clear_wait, cfg)
+
+    cfg.num_threads = 2
+    cfg.target = channels - cfg.num_threads
+    ethtool(f"-X {cfg.ifname} equal {cfg.target}")
+    defer(ethtool, f"-X {cfg.ifname} default")
+
+    rss_ctx_id = create_rss_ctx_multi(cfg, cfg.target, cfg.num_threads)
+    defer(ethtool, f"-X {cfg.ifname} delete context {rss_ctx_id}")
+
+    flow_rule_id = set_flow_rule_rss(cfg, rss_ctx_id)
+    defer(ethtool, f"-N {cfg.ifname} delete {flow_rule_id}")
+
+
 @ksft_variants([
     KsftNamedVariant("single", single),
     KsftNamedVariant("rss", rss),
+    KsftNamedVariant("rss_multiqueue", rss_multiqueue),
 ])
 def test_zcrx(cfg, setup) -> None:
     cfg.require_ipver('6')
     _require_ntuple(cfg)
 
+    cfg.num_threads = 1
+
     setup(cfg)
-    rx_cmd = f"{cfg.bin_local} -s -p {cfg.port} -i {cfg.ifname} -q {cfg.target}"
-    tx_cmd = f"{cfg.bin_remote} -c -h {cfg.addr_v['6']} -p {cfg.port} -l 12840"
+
+    rx_cmd = (f"{cfg.bin_local} -s -p {cfg.port} -i {cfg.ifname} "
+              f"-q {cfg.target} -t {cfg.num_threads}")
+    tx_cmd = (f"{cfg.bin_remote} -c -h {cfg.addr_v['6']} -p {cfg.port} "
+              f"-l 12840 -t {cfg.num_threads}")
     with bkg(rx_cmd, exit_wait=True):
         wait_port_listen(cfg.port, proto="tcp")
         cmd(tx_cmd, host=cfg.remote)
-- 
2.53.0-Meta

Re: [PATCH net-next v5 5/6] selftests: net: add multithread server support to iou-zcrx

[David Wei]

On 2026-08-13 18:23, Juanlu Herrero wrote:
> Run the iou-zcrx server as N worker threads, each owning one receive
> queue with its own io_uring and zero-copy receive (zcrx) ifq, so the
> test can exercise multi-queue zero-copy receive.
> 
> The main thread owns the listening socket, accepts connections, and
> dispatches each to the worker owning the queue it landed on by matching
> SO_INCOMING_NAPI_ID against per-queue NAPI IDs.
> 
> Assisted-by: Claude:claude-opus-4-8
> Signed-off-by: Juanlu Herrero <juanlu@fastmail.com>
> ---
>   .../testing/selftests/drivers/net/hw/Makefile |   5 +-
>   .../selftests/drivers/net/hw/iou-zcrx.c       | 262 +++++++++++++-----
>   2 files changed, 195 insertions(+), 72 deletions(-)
> 
[...]
> diff --git a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
> index f793a6c04e412..008d3f4b76263 100644
> --- a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
> +++ b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
[...]
> @@ -289,12 +279,13 @@ static void process_recvzc(struct thread_ctx *ctx, struct io_uring_cqe *cqe)
>   		error(1, 0, "recvzc(): %d", cqe->res);
>   
>   	if (cfg_oneshot) {
> -		if (cqe->res == 0 && cqe->flags == 0 && cfg_oneshot_recvs) {
> -			add_recvzc_oneshot(ctx, ctx->connfd, page_size);
> -			cfg_oneshot_recvs--;
> +		if (cqe->res == 0 && cqe->flags == 0 &&
> +		    ctx->oneshot_recvs[conn_idx]) {
> +			add_recvzc_oneshot(ctx, conn_idx, page_size);
> +			ctx->oneshot_recvs[conn_idx]--;

This needs an early return. Sorry the bug was pre-existing but I just
noticed it.

Re: [PATCH net-next v5 6/6] selftests: net: add rss_multiqueue test variant to iou-zcrx

[David Wei]

On 2026-08-13 18:23, Juanlu Herrero wrote:
> Add a rss_multiqueue Python test variant that exercises multi-queue
> zero-copy receive on a single listening socket.
> 
> Assisted-by: Claude:claude-opus-4-8
> Signed-off-by: Juanlu Herrero <juanlu@fastmail.com>
> ---
>   .../selftests/drivers/net/hw/iou-zcrx.py      | 50 ++++++++++++++++++-
>   1 file changed, 48 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/drivers/net/hw/iou-zcrx.py b/tools/testing/selftests/drivers/net/hw/iou-zcrx.py
> index b7a225fe4beae..c833535d8a03c 100755
> --- a/tools/testing/selftests/drivers/net/hw/iou-zcrx.py
> +++ b/tools/testing/selftests/drivers/net/hw/iou-zcrx.py
> @@ -30,6 +30,13 @@ def create_rss_ctx(cfg):
>       return int(values)
>   
>   
> +def create_rss_ctx_multi(cfg, start, count):
> +    """Create an RSS context spanning count queues from start, return its ID."""
> +    output = ethtool(f"-X {cfg.ifname} context new start {start} equal {count}").stdout
> +    values = re.search(r'New RSS context is (\d+)', output).group(1)
> +    return int(values)
> +
> +
>   def set_flow_rule(cfg):
>       output = ethtool(f"-N {cfg.ifname} flow-type tcp6 dst-port {cfg.port} action {cfg.target}").stdout
>       values = re.search(r'ID (\d+)', output).group(1)
> @@ -127,17 +134,56 @@ def _require_ntuple(cfg):
>           defer(ethtool, f"-K {cfg.ifname} ntuple-filters off")
>   
>   
> +def rss_multiqueue(cfg):
> +    """Steer the test flow to a multi-queue RSS context for multi-thread zcrx."""
> +    channels = cfg.ethnl.channels_get({'header': {'dev-index': cfg.ifindex}})
> +    channels = channels['combined-count']
> +    if channels < 3:
> +        raise KsftSkipEx('Test requires NETIF with at least 3 combined channels')
> +
> +    rings = cfg.ethnl.rings_get({'header': {'dev-index': cfg.ifindex}})
> +    rx_rings = rings['rx']
> +    hds_thresh = rings.get('hds-thresh', 0)
> +
> +    cfg.ethnl.rings_set({'header': {'dev-index': cfg.ifindex},
> +                         'tcp-data-split': 'enabled',
> +                         'hds-thresh': 0,
> +                         'rx': 64})
> +    defer(cfg.ethnl.rings_set, {'header': {'dev-index': cfg.ifindex},
> +                                'tcp-data-split': 'unknown',
> +                                'hds-thresh': hds_thresh,
> +                                'rx': rx_rings})
> +    defer(mp_clear_wait, cfg)
> +
> +    cfg.num_threads = 2
> +    cfg.target = channels - cfg.num_threads
> +    ethtool(f"-X {cfg.ifname} equal {cfg.target}")
> +    defer(ethtool, f"-X {cfg.ifname} default")
> +
> +    rss_ctx_id = create_rss_ctx_multi(cfg, cfg.target, cfg.num_threads)
> +    defer(ethtool, f"-X {cfg.ifname} delete context {rss_ctx_id}")
> +
> +    flow_rule_id = set_flow_rule_rss(cfg, rss_ctx_id)
> +    defer(ethtool, f"-N {cfg.ifname} delete {flow_rule_id}")
> +
> +
>   @ksft_variants([
>       KsftNamedVariant("single", single),
>       KsftNamedVariant("rss", rss),
> +    KsftNamedVariant("rss_multiqueue", rss_multiqueue),
>   ])
>   def test_zcrx(cfg, setup) -> None:
>       cfg.require_ipver('6')
>       _require_ntuple(cfg)
>   
> +    cfg.num_threads = 1
> +
>       setup(cfg)
> -    rx_cmd = f"{cfg.bin_local} -s -p {cfg.port} -i {cfg.ifname} -q {cfg.target}"
> -    tx_cmd = f"{cfg.bin_remote} -c -h {cfg.addr_v['6']} -p {cfg.port} -l 12840"
> +
> +    rx_cmd = (f"{cfg.bin_local} -s -p {cfg.port} -i {cfg.ifname} "
> +              f"-q {cfg.target} -t {cfg.num_threads}")
> +    tx_cmd = (f"{cfg.bin_remote} -c -h {cfg.addr_v['6']} -p {cfg.port} "
> +              f"-l 12840 -t {cfg.num_threads}")
>       with bkg(rx_cmd, exit_wait=True):
>           wait_port_listen(cfg.port, proto="tcp")
>           cmd(tx_cmd, host=cfg.remote)

Reviewed-by: David Wei <dw@davidwei.uk>

Re: [PATCH net-next v5 4/6] selftests: net: add multithread client support to iou-zcrx

[David Wei]

On 2026-08-13 18:23, Juanlu Herrero wrote:
> Add pthreads to the iou-zcrx client so that multiple connections can be
> established simultaneously. Each client thread connects to the server
> and sends its payload independently.
> 
> Introduce the -t option to control the number of threads (default 1),
> preserving backwards compatibility with existing tests.
> 
> Assisted-by: Claude:claude-opus-4-8
> Signed-off-by: Juanlu Herrero <juanlu@fastmail.com>
> ---
>   .../testing/selftests/drivers/net/hw/Makefile |  2 +-
>   .../selftests/drivers/net/hw/iou-zcrx.c       | 35 +++++++++++++++++--
>   2 files changed, 33 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/testing/selftests/drivers/net/hw/Makefile b/tools/testing/selftests/drivers/net/hw/Makefile
> index 78bb0169350b2..37023ba580de7 100644
> --- a/tools/testing/selftests/drivers/net/hw/Makefile
> +++ b/tools/testing/selftests/drivers/net/hw/Makefile
> @@ -91,5 +91,5 @@ include ../../../net/ynl.mk
>   include ../../../net/bpf.mk
>   
>   ifeq ($(HAS_IOURING_ZCRX),y)
> -$(OUTPUT)/iou-zcrx: LDLIBS += -luring
> +$(OUTPUT)/iou-zcrx: LDLIBS += -luring -lpthread
>   endif
> diff --git a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
> index 9b62fd0703e61..f793a6c04e412 100644
> --- a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
> +++ b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
> @@ -4,6 +4,7 @@
>   #include <error.h>
>   #include <fcntl.h>
>   #include <limits.h>
> +#include <pthread.h>
>   #include <stdbool.h>
>   #include <stdint.h>
>   #include <stdio.h>
> @@ -85,6 +86,7 @@ static int cfg_send_size = SEND_SIZE;
>   static struct sockaddr_in6 cfg_addr;
>   static unsigned int cfg_rx_buf_len;
>   static bool cfg_dry_run;
> +static int cfg_num_threads = 1;
>   
>   static char *payload;
>   
> @@ -379,7 +381,7 @@ static void run_server(void)
>   		error(1, 0, "test failed\n");
>   }
>   
> -static void run_client(void)
> +static void *client_worker(void *arg)
>   {
>   	ssize_t to_send = cfg_send_size;
>   	ssize_t sent = 0;
> @@ -405,12 +407,36 @@ static void run_client(void)
>   	}
>   
>   	close(fd);
> +	return NULL;
> +}
> +
> +static void run_client(void)
> +{
> +	int total_conns = cfg_num_threads * cfg_num_threads;
> +	pthread_t *threads;
> +	int i, ret;
> +
> +	threads = calloc(total_conns, sizeof(*threads));
> +	if (!threads)
> +		error(1, 0, "calloc()");
> +
> +	for (i = 0; i < total_conns; i++) {
> +		ret = pthread_create(&threads[i], NULL, client_worker, NULL);
> +		if (ret)
> +			error(1, ret, "pthread_create()");
> +	}
> +
> +	for (i = 0; i < total_conns; i++)
> +		pthread_join(threads[i], NULL);
> +
> +	free(threads);
>   }
>   
>   static void usage(const char *filepath)
>   {
>   	error(1, 0, "Usage: %s (-4|-6) (-s|-c) -h<server_ip> -p<port> "
> -		    "-l<payload_size> -i<ifname> -q<rxq_id>", filepath);
> +		    "-l<payload_size> -i<ifname> -q<rxq_id> -t<num_threads>",
> +		    filepath);
>   }
>   
>   static void parse_opts(int argc, char **argv)
> @@ -428,7 +454,7 @@ static void parse_opts(int argc, char **argv)
>   		usage(argv[0]);
>   	cfg_payload_len = max_payload_len;
>   
> -	while ((c = getopt(argc, argv, "sch:p:l:i:q:o:z:x:d")) != -1) {
> +	while ((c = getopt(argc, argv, "sch:p:l:i:q:o:z:x:dt:")) != -1) {
>   		switch (c) {
>   		case 's':
>   			if (cfg_client)
> @@ -469,6 +495,9 @@ static void parse_opts(int argc, char **argv)
>   		case 'd':
>   			cfg_dry_run = true;
>   			break;
> +		case 't':
> +			cfg_num_threads = strtoul(optarg, NULL, 0);
> +			break;
>   		}
>   	}
>   

Reviewed-by: David Wei <dw@davidwei.uk>

Re: [PATCH net-next v5 3/6] selftests: net: refactor server state into struct thread_ctx

[David Wei]

On 2026-08-13 18:23, Juanlu Herrero wrote:
> Move server-side state (io_uring ring, zcrx area, refill ring, receive
> tracking) from global variables into a local struct thread_ctx. This is
> a pure refactor with no behavior change: run_server still allocates a
> single context on the stack and runs single-threaded, using io_uring
> accept and recvzc as before.
> 
> This prepares the ground for the multithread server support in the
> following commits, which spawns N worker threads each with their own
> struct thread_ctx.
> 
> Assisted-by: Claude:claude-opus-4-8
> Signed-off-by: Juanlu Herrero <juanlu@fastmail.com>
> ---
>   .../selftests/drivers/net/hw/iou-zcrx.c       | 156 +++++++++---------
>   1 file changed, 80 insertions(+), 76 deletions(-)
> 
> diff --git a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
> index c6dbd0ad53681..9b62fd0703e61 100644
> --- a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
> +++ b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
> @@ -87,14 +87,18 @@ static unsigned int cfg_rx_buf_len;
>   static bool cfg_dry_run;
>   
>   static char *payload;
> -static void *area_ptr;
> -static void *ring_ptr;
> -static size_t ring_size;
> -static struct io_uring_zcrx_rq rq_ring;
> -static unsigned long area_token;
> -static int connfd;
> -static bool stop;
> -static size_t received;
> +
> +struct thread_ctx {
> +	struct io_uring		ring;
> +	void			*area_ptr;
> +	void			*ring_ptr;
> +	size_t			ring_size;
> +	struct io_uring_zcrx_rq	rq_ring;
> +	unsigned long		area_token;
> +	int			connfd;
> +	bool			stop;
> +	size_t			received;
> +};
>   
>   static unsigned long gettimeofday_ms(void)
>   {
> @@ -138,7 +142,7 @@ static inline size_t get_refill_ring_size(unsigned int rq_entries)
>   	return ALIGN_UP(size, page_size);
>   }
>   
> -static void setup_zcrx(struct io_uring *ring)
> +static void setup_zcrx(struct thread_ctx *ctx)
>   {
>   	unsigned int ifindex;
>   	unsigned int rq_entries = 4096;
> @@ -149,44 +153,44 @@ static void setup_zcrx(struct io_uring *ring)
>   		error(1, 0, "bad interface name: %s", cfg_ifname);
>   
>   	if (cfg_rx_buf_len && cfg_rx_buf_len != page_size) {
> -		area_ptr = mmap(NULL,
> -				AREA_SIZE,
> -				PROT_READ | PROT_WRITE,
> -				MAP_ANONYMOUS | MAP_PRIVATE |
> -				MAP_HUGETLB | MAP_HUGE_2MB,
> -				-1,
> -				0);
> -		if (area_ptr == MAP_FAILED) {
> +		ctx->area_ptr = mmap(NULL,
> +				     AREA_SIZE,
> +				     PROT_READ | PROT_WRITE,
> +				     MAP_ANONYMOUS | MAP_PRIVATE |
> +				     MAP_HUGETLB | MAP_HUGE_2MB,
> +				     -1,
> +				     0);
> +		if (ctx->area_ptr == MAP_FAILED) {
>   			printf("Can't allocate huge pages\n");
>   			exit(SKIP_CODE);
>   		}
>   	} else {
> -		area_ptr = mmap(NULL,
> -				AREA_SIZE,
> -				PROT_READ | PROT_WRITE,
> -				MAP_ANONYMOUS | MAP_PRIVATE,
> -				0,
> -				0);
> -		if (area_ptr == MAP_FAILED)
> +		ctx->area_ptr = mmap(NULL,
> +				     AREA_SIZE,
> +				     PROT_READ | PROT_WRITE,
> +				     MAP_ANONYMOUS | MAP_PRIVATE,
> +				     0,
> +				     0);
> +		if (ctx->area_ptr == MAP_FAILED)
>   			error(1, 0, "mmap(): zero copy area");
>   	}
>   
> -	ring_size = get_refill_ring_size(rq_entries);
> -	ring_ptr = mmap(NULL,
> -			ring_size,
> -			PROT_READ | PROT_WRITE,
> -			MAP_ANONYMOUS | MAP_PRIVATE,
> -			0,
> -			0);
> +	ctx->ring_size = get_refill_ring_size(rq_entries);
> +	ctx->ring_ptr = mmap(NULL,
> +			     ctx->ring_size,
> +			     PROT_READ | PROT_WRITE,
> +			     MAP_ANONYMOUS | MAP_PRIVATE,
> +			     0,
> +			     0);
>   
>   	struct io_uring_region_desc region_reg = {
> -		.size = ring_size,
> -		.user_addr = (__u64)(unsigned long)ring_ptr,
> +		.size = ctx->ring_size,
> +		.user_addr = (__u64)(unsigned long)ctx->ring_ptr,
>   		.flags = IORING_MEM_REGION_TYPE_USER,
>   	};
>   
>   	struct io_uring_zcrx_area_reg area_reg = {
> -		.addr = (__u64)(unsigned long)area_ptr,
> +		.addr = (__u64)(unsigned long)ctx->area_ptr,
>   		.len = AREA_SIZE,
>   		.flags = 0,
>   	};
> @@ -200,7 +204,7 @@ static void setup_zcrx(struct io_uring *ring)
>   		.rx_buf_len = cfg_rx_buf_len,
>   	};
>   
> -	ret = io_uring_register_ifq(ring, (void *)&reg);
> +	ret = io_uring_register_ifq(&ctx->ring, (void *)&reg);
>   	if (cfg_rx_buf_len && (ret == -EINVAL || ret == -EOPNOTSUPP ||
>   			       ret == -ERANGE)) {
>   		printf("Large chunks are not supported %i\n", ret);
> @@ -209,64 +213,64 @@ static void setup_zcrx(struct io_uring *ring)
>   		error(1, 0, "io_uring_register_ifq(): %d", ret);
>   	}
>   
> -	rq_ring.khead = (unsigned int *)((char *)ring_ptr + reg.offsets.head);
> -	rq_ring.ktail = (unsigned int *)((char *)ring_ptr + reg.offsets.tail);
> -	rq_ring.rqes = (struct io_uring_zcrx_rqe *)((char *)ring_ptr + reg.offsets.rqes);
> -	rq_ring.rq_tail = 0;
> -	rq_ring.ring_entries = reg.rq_entries;
> +	ctx->rq_ring.khead = (unsigned int *)((char *)ctx->ring_ptr + reg.offsets.head);
> +	ctx->rq_ring.ktail = (unsigned int *)((char *)ctx->ring_ptr + reg.offsets.tail);
> +	ctx->rq_ring.rqes = (struct io_uring_zcrx_rqe *)((char *)ctx->ring_ptr + reg.offsets.rqes);
> +	ctx->rq_ring.rq_tail = 0;
> +	ctx->rq_ring.ring_entries = reg.rq_entries;
>   
> -	area_token = area_reg.rq_area_token;
> +	ctx->area_token = area_reg.rq_area_token;
>   }
>   
> -static void add_accept(struct io_uring *ring, int sockfd)
> +static void add_accept(struct thread_ctx *ctx, int sockfd)
>   {
>   	struct io_uring_sqe *sqe;
>   
> -	sqe = io_uring_get_sqe(ring);
> +	sqe = io_uring_get_sqe(&ctx->ring);
>   
>   	io_uring_prep_accept(sqe, sockfd, NULL, NULL, 0);
>   	sqe->user_data = 1;
>   }
>   
> -static void add_recvzc(struct io_uring *ring, int sockfd)
> +static void add_recvzc(struct thread_ctx *ctx, int sockfd)
>   {
>   	struct io_uring_sqe *sqe;
>   
> -	sqe = io_uring_get_sqe(ring);
> +	sqe = io_uring_get_sqe(&ctx->ring);
>   
>   	io_uring_prep_rw(IORING_OP_RECV_ZC, sqe, sockfd, NULL, 0, 0);
>   	sqe->ioprio |= IORING_RECV_MULTISHOT;
>   	sqe->user_data = 2;
>   }
>   
> -static void add_recvzc_oneshot(struct io_uring *ring, int sockfd, size_t len)
> +static void add_recvzc_oneshot(struct thread_ctx *ctx, int sockfd, size_t len)
>   {
>   	struct io_uring_sqe *sqe;
>   
> -	sqe = io_uring_get_sqe(ring);
> +	sqe = io_uring_get_sqe(&ctx->ring);
>   
>   	io_uring_prep_rw(IORING_OP_RECV_ZC, sqe, sockfd, NULL, len, 0);
>   	sqe->ioprio |= IORING_RECV_MULTISHOT;
>   	sqe->user_data = 2;
>   }
>   
> -static void process_accept(struct io_uring *ring, struct io_uring_cqe *cqe)
> +static void process_accept(struct thread_ctx *ctx, struct io_uring_cqe *cqe)
>   {
>   	if (cqe->res < 0)
>   		error(1, 0, "accept()");
> -	if (connfd)
> +	if (ctx->connfd)
>   		error(1, 0, "Unexpected second connection");
>   
> -	connfd = cqe->res;
> +	ctx->connfd = cqe->res;
>   	if (cfg_oneshot)
> -		add_recvzc_oneshot(ring, connfd, page_size);
> +		add_recvzc_oneshot(ctx, ctx->connfd, page_size);
>   	else
> -		add_recvzc(ring, connfd);
> +		add_recvzc(ctx, ctx->connfd);
>   }
>   
> -static void process_recvzc(struct io_uring *ring, struct io_uring_cqe *cqe)
> +static void process_recvzc(struct thread_ctx *ctx, struct io_uring_cqe *cqe)
>   {
> -	unsigned rq_mask = rq_ring.ring_entries - 1;
> +	unsigned int rq_mask = ctx->rq_ring.ring_entries - 1;
>   	struct io_uring_zcrx_cqe *rcqe;
>   	struct io_uring_zcrx_rqe *rqe;
>   	uint64_t mask;
> @@ -275,7 +279,7 @@ static void process_recvzc(struct io_uring *ring, struct io_uring_cqe *cqe)
>   	int i;
>   
>   	if (cqe->res == 0 && cqe->flags == 0 && cfg_oneshot_recvs == 0) {
> -		stop = true;
> +		ctx->stop = true;
>   		return;
>   	}
>   
> @@ -284,56 +288,56 @@ static void process_recvzc(struct io_uring *ring, struct io_uring_cqe *cqe)
>   
>   	if (cfg_oneshot) {
>   		if (cqe->res == 0 && cqe->flags == 0 && cfg_oneshot_recvs) {
> -			add_recvzc_oneshot(ring, connfd, page_size);
> +			add_recvzc_oneshot(ctx, ctx->connfd, page_size);
>   			cfg_oneshot_recvs--;
>   		}
>   	} else if (!(cqe->flags & IORING_CQE_F_MORE)) {
> -		add_recvzc(ring, connfd);
> +		add_recvzc(ctx, ctx->connfd);
>   	}
>   
>   	rcqe = (struct io_uring_zcrx_cqe *)(cqe + 1);
>   
>   	n = cqe->res;
>   	mask = (1ULL << IORING_ZCRX_AREA_SHIFT) - 1;
> -	data = (char *)area_ptr + (rcqe->off & mask);
> +	data = (char *)ctx->area_ptr + (rcqe->off & mask);
>   
>   	for (i = 0; i < n; i++) {
> -		if (*(data + i) != payload[(received + i)])
> +		if (*(data + i) != payload[(ctx->received + i)])
>   			error(1, 0, "payload mismatch at %d", i);
>   	}
> -	received += n;
> +	ctx->received += n;
>   
> -	rqe = &rq_ring.rqes[(rq_ring.rq_tail & rq_mask)];
> -	rqe->off = (rcqe->off & ~IORING_ZCRX_AREA_MASK) | area_token;
> +	rqe = &ctx->rq_ring.rqes[(ctx->rq_ring.rq_tail & rq_mask)];
> +	rqe->off = (rcqe->off & ~IORING_ZCRX_AREA_MASK) | ctx->area_token;
>   	rqe->len = cqe->res;
> -	io_uring_smp_store_release(rq_ring.ktail, ++rq_ring.rq_tail);
> +	io_uring_smp_store_release(ctx->rq_ring.ktail, ++ctx->rq_ring.rq_tail);
>   }
>   
> -static void server_loop(struct io_uring *ring)
> +static void server_loop(struct thread_ctx *ctx)
>   {
>   	struct io_uring_cqe *cqe;
>   	unsigned int count = 0;
>   	unsigned int head;
>   	int i, ret;
>   
> -	io_uring_submit_and_wait(ring, 1);
> +	io_uring_submit_and_wait(&ctx->ring, 1);
>   
> -	io_uring_for_each_cqe(ring, head, cqe) {
> +	io_uring_for_each_cqe(&ctx->ring, head, cqe) {
>   		if (cqe->user_data == 1)
> -			process_accept(ring, cqe);
> +			process_accept(ctx, cqe);
>   		else if (cqe->user_data == 2)
> -			process_recvzc(ring, cqe);
> +			process_recvzc(ctx, cqe);
>   		else
>   			error(1, 0, "unknown cqe");
>   		count++;
>   	}
> -	io_uring_cq_advance(ring, count);
> +	io_uring_cq_advance(&ctx->ring, count);
>   }
>   
>   static void run_server(void)
>   {
> +	struct thread_ctx ctx = {};
>   	unsigned int flags = 0;
> -	struct io_uring ring;
>   	int fd, enable, ret;
>   	uint64_t tstop;
>   
> @@ -356,22 +360,22 @@ static void run_server(void)
>   	flags |= IORING_SETUP_SUBMIT_ALL;
>   	flags |= IORING_SETUP_CQE32;
>   
> -	io_uring_queue_init(512, &ring, flags);
> +	io_uring_queue_init(512, &ctx.ring, flags);
>   
> -	setup_zcrx(&ring);
> +	setup_zcrx(&ctx);
>   	if (cfg_dry_run)
>   		return;
>   
>   	if (listen(fd, 1024) < 0)
>   		error(1, 0, "listen()");
>   
> -	add_accept(&ring, fd);
> +	add_accept(&ctx, fd);
>   
>   	tstop = gettimeofday_ms() + 5000;
> -	while (!stop && gettimeofday_ms() < tstop)
> -		server_loop(&ring);
> +	while (!ctx.stop && gettimeofday_ms() < tstop)
> +		server_loop(&ctx);
>   
> -	if (!stop)
> +	if (!ctx.stop)
>   		error(1, 0, "test failed\n");
>   }
>   

Reviewed-by: David Wei <dw@davidwei.uk>